BATCH-1759: re-instate clear() in HibernateItemWriter

spring-batch-infrastructure/src/main/java/org/springframework/batch/item/database/HibernateItemWriter.java

@@ -29,7 +29,8 @@ import org.springframework.util.Assert;
 /**
  * {@link ItemWriter} that uses a Hibernate session to save or update entities
  * that are not part of the current Hibernate session. It will also flush the
- * session at chunk boundaries.<br/>
+ * session at chunk boundaries. It will also flush and clear the session at
+ * chunk boundaries by default (@see ).<br/>
  * <br/>
  * 
  * The writer is thread safe after its properties are set (normal singleton
@@ -45,6 +46,18 @@ public class HibernateItemWriter<T> implements ItemWriter<T>, InitializingBean {
 
 	private HibernateOperations hibernateTemplate;
 
+	private boolean clearSession = true;
+
+	/**
+	 * Flag to indicate that the session should be cleared and flushed at the
+	 * end of the write (default true).
+	 * 
+	 * @param clearSession the flag value to set
+	 */
+	public void setClearSession(boolean clearSession) {
+		this.clearSession = clearSession;
+	}
+
 	/**
 	 * Public setter for the {@link HibernateOperations} property.
 	 * 
@@ -80,6 +93,9 @@ public class HibernateItemWriter<T> implements ItemWriter<T>, InitializingBean {
 	public final void write(List<? extends T> items) {
 		doWrite(hibernateTemplate, items);
 		hibernateTemplate.flush();
+		if (clearSession) {
+			hibernateTemplate.clear();
+		}
 	}
 
 	/**